Angiogenesis is known to involve in the pathogenesis of various diseases such as solid tumors, proliferative retinopathies, age-related macular degeneration (AMD), and rheumatoid arthritis. Vascular endothelial growth factor (VEGF), one of the factors necessary for angiogenesis, is expressed in human cancers and plays an important role in tumor neoangiogenesis. In addition, the presence of VEGF in a high concentration in the eye fluid is highly correlated with the vascularization activity in diabetic and other ischemic retinopathy patients (Aiello L P, et al., N Engl J Med 1994; 331: 1480-1487) and leads to localization of growth factors in the choroidal neovascular membranes of age-related macular degeneration (AMD) patients (Amin R1, et al. Invest Ophthalmol Vis Sci. 1994 Jul.; 35(8): 3178-88). Therefore, anti-VEGF antibodies or VEGF inhibitors may be promising candidates for the treatment of solid tumor and diseases associated with angiogenesis in the eye.
Aflibercept, one of the VEGF inhibitors, is a recombinant fusion protein consisting of VEGF-binding portions from the extracellular domains of human VEGF receptors 1 and 2 that are fused to the Fc portion of the human IgG1 immunoglobulin. Aflibercept has been approved in the United States and Europe for the treatment of wet macular degeneration under the trade name Eylea™.
Physicochemical modifications occur in protein-containing pharmaceutical compositions under the non-optimal condition. In particular, factors such as concentration of a protein, type of buffering agents, type and concentration of stabilizing agents, type and concentration of organic co-solvents, concentration of a salt, pH, temperature, and contact with air, significantly affect oxidation, deamidation, isomerization, and polymerization of a protein. These modifications cause aggregations, fragments, isomers of the protein, so that the biological activity thereof may be reduced. Especially, protein aggregation, which is a major internal factor in the formation of insoluble microparticles, may cause side effects such as immune reactions. And also, because of the characteristics of ophthalmic formulations, the insoluble particles should be strictly restricted or controlled.
Korean Patent No. 10-1406811 (International Patent Publication No. WO 2007/149334) has disclosed an ophthalmic formulation and a lyophilizable formulation having pH 5.8 to 7.0, which comprises aflibercept; an organic co-solvent such as polysorbate; an ionic tonicity agent selected from sodium chloride or potassium chloride; a sodium phosphate buffering agent; and a stabilizer such as sucrose, each being in a specific concentration. The formulation disclosed in Korean Patent No. 10-1406811 may be applied to a prefilled syringe suitable for intravitreal administration.
It has been described that the ophthalmic formulation and lyophilizable formulation disclosed in Korean Patent No. 10-1406811 have an effect of inhibiting production of impurities and byproducts due to aggregation, fragmentation and isomerization of aflibercept. However, said formulations were problematic in that the effect of stabilizing aflibercept was markedly reduced under the stress condition, e.g., under high temperature condition of 40° C. or more (Korean Patent Publication No. 10-2017-0000356).